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Cryptography allows information to be seen only by those authorized to see it, and hides the information from everyone else. By using cryptography, we can prove the identity of users. The system works by generating keys that are used to maintain information confidentiality and integrity.

There are various types of cryptography. Transposition and substitution use algorithms to scramble plain texts. Symmetric cryptography uses the same key to encrypt and decrypt the text (shared secret); the Data Encryption Standard uses this type of cryptography. On the other hand, asymmetric key cryptography is when different keys are used at the sending and receiving ends. The commonly used public-private key system used to identify users and maintain confidentiality is a form of asymmetric cryptography.

Cryptography methods include the different use of keys.  When encrypting and decrypting the key is used, but with each method there is either one key used for both encryption and decryption (symmetrical) or one key for each end (asymmetrical). The algorithms may be made public but it is important to keep the key secret, a cryptosystem is considered strong until it is cracked.

Regardless of the type of cryptography, a strong cryptosystem will be made of a strong key to prevent cracking the code easily. The key should also appear as random as possible to prevent the detection of a pattern. The system should also provide a resistance to all known attacks. Finally, a cryptosystem is not reliable until it had been exposed to brute force attacks and survive.